Electron gun adjustment in a vacuum

ABSTRACT

Embodiments include a vacuum device, comprising: an enclosure configured to enclose a vacuum, the enclosure including an external base including an opening; an internal base within the enclosure; and an adjustable support assembly adjustably coupling the internal base to the external base and extending through the opening, the adjustable support assembly comprising: a threaded shaft extending along a longitudinal axis and coupled to the internal base; a threaded hole component threadedly engaged with the threaded shaft and coupled to the external base such that the threaded hole component is axially constrained in a direction along the longitudinal axis relative to the external base independent of the threaded shaft; and a flexible component coupled to the external base and the threaded shaft and sealing the opening.

RELATED APPLICATIONS

The present application claims priority U.S. Provisional PatentApplication No. 62/548,387, which was filed on Aug. 21, 2017, entitled“Electron Gun Adjustment in A Vacuum and Electron Gun ThermalDissipation,” which is assigned to the assignee of the presentinvention, and is incorporated by reference herein.

BACKGROUND

Unless otherwise indicated herein, the approaches described in thissection are not prior art to the claims in this disclosure and are notadmitted to be prior art by inclusion in this section.

Linear beam electron devices are used in sophisticated medical, securityinspection, communication, and radar systems that require amplificationof a radio frequency (RF) or microwave electromagnetic signal. Anelectron gun is a component in some vacuum devices (e.g., electrondevices, vacuum electron devices, or vacuum electric devices) thatideally produces a collimated electron beam that has a precise kineticenergy. The electron gun can be used in microwave linear beam vacuumtubes, such as klystrons, inductive output tubes, travelling wave tubes(TWT), backward wave oscillators, and gyrotrons, as well as inscientific instruments, such as electron microscopes, betatrons, andparticle accelerators (e.g., linear particle accelerator [linac]).Electron guns may be classified by the type of electric field generation(e.g., direct current [DC] or radio frequency [RF]), by emissionmechanism (e.g., thermionic, photocathode, field emission, or plasmassource), by focusing (pure electrostatic or with magnetic fields), andby the number of electrodes.

A conventional klystron is an example of a linear beam electron deviceused as a microwave amplifier that includes an electron gun. In aklystron, an electron beam is formed by applying a voltage potentialbetween a cathode emitting electrons and an anode, accelerating theseemitted electrons such that the cathode is at a more negative voltagewith respect to the anode. The electrons originating at the cathode ofan electron gun thereafter propagate through a drift tube, also called abeam tunnel, and are received by a collector assembly.

Depending on the size of the vacuum device, a cathode assembly (e.g.,including the cathode, focus electrode, and associated heater assembly)of the electron gun assembly of the vacuum device can be quite large orheavy and difficult to align with the rest of the device (e.g., thedrift tube or the beam tunnel). The support and alignment of electronguns used in high power microwave devices and accelerators can affectthe operation of the device or accelerator. In large klystrons, and inparticular sheet beam klystrons (SBKs), the cathode assembly can weighover 20 pounds (lbs; 9 kilograms [kg]), and in some klystrons thecathode assembly can even weigh over 50 lbs (23 kg). The technology(systems, devices, and methods) described herein provides mechanisms tosupport and align an electron gun in a vacuum device.

Often during operation, the cathode assembly can generate an excessiveamount of heat and thermal stress, i.e., high thermal load. The heat andthermal stresses on the components of the vacuum device, especially thecathode assembly, can lead to stress values greater than the yieldstrength of critical components of the vacuum device, such as thesupport and alignment features. The technology (systems, devices, andmethods) described herein provides mechanism to increase thermaldissipation (i.e., decrease thermal loading) in particular locations ofthe electron gun, such as the support structure or alignment features.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrate a block diagram of an example klystron.

FIG. 2 illustrates a perspective view of an example sheet beam klystron(SBK).

FIGS. 3A-3B illustrate perspective views of an example cathode assemblyfor a SBK.

FIGS. 4-5 illustrate perspective half cross-sectional views of anexample cathode assembly.

FIGS. 6A-6B illustrate quarter cross-sectional views of an exampleadjustable support assembly of a cathode assembly.

FIG. 7 illustrates cross-sectional view of an example adjustable supportassembly.

FIG. 8 illustrates perspective cross-sectional view of an exampleadjustable support assembly.

FIG. 8A illustrates an expanded view of threads between a linear shaftand a drive bushing of an example adjustable support assembly.

FIG. 9A illustrates cross-sectional view of an example adjustablesupport assembly with a flexible diaphragm component.

FIG. 9B illustrates cross-sectional view of an example adjustablesupport assembly with a flexible bellows component.

FIG. 10 is a block diagram of an example of an adjustable supportassembly in a vacuum device.

FIGS. 11A-B are block diagrams of examples of support assemblies with athermal dissipative structure according to some embodiments.

FIGS. 12A-12B illustrate views of an example thermal dissipative strapassembly.

FIG. 13 illustrates a perspective cross-sectional view of an examplecathode assembly with adjustable support assemblies, thermal dissipativestrap assemblies, and cathode heater connectors.

FIG. 14A-14B illustrate perspective views of an example cathode assemblywith adjustable support assemblies and thermal dissipative strapassemblies.

FIG. 14C illustrates a perspective view of base plate indexing forthermal dissipative strap assemblies and adjustable support assemblies.

FIG. 15 illustrates a top view of an example cathode assembly withadjustable support assemblies, thermal dissipative strap assemblies, andcathode heater connectors.

FIG. 16 illustrates a perspective view of an example cathode assemblywith three thermal dissipative strap assemblies.

DETAILED DESCRIPTION OF SOME EXAMPLE EMBODIMENTS

Before any embodiments are explained in detail, it is to be understoodthat all embodiments are not limited to the particular details ofconstruction and the arrangement of components set forth in thefollowing description or illustrated in the following drawings. Otherembodiments may be practiced or carried out in various ways and mayinclude various modifications. Numbers provided in flow charts andprocesses are provided for clarity in illustrating steps and operationsand do not necessarily indicate a particular order or sequence. Unlessotherwise defined, the term “or” can refer to a choice of alternatives(e.g., a disjunction operator, or an exclusive or) or a combination ofthe alternatives (e.g., a conjunction operator, and/or, a logical or, ora Boolean OR).

Some embodiments relate generally to alignment of components within anevacuated enclosure of a vacuum device while the device is still undervacuum, and more particularly, to various mechanism and components foraligning an electron gun or a cathode assembly component (e.g., acathode, or a focus electrode) without disrupting the vacuum in thevacuum device.

In addition, some embodiments relate generally to thermally dissipativefeatures to dissipate heat from support features and structures withinthe evacuated enclosure of the vacuum device, and more particularly, tothermal dissipative straps to transfer heat away from adjustablesupports.

Reference will now be made to the drawings to describe various aspectsof example embodiments. It is to be understood that the drawings arediagrammatic and schematic representations of such example embodiments,and are not limiting of all embodiments, nor are they necessarily drawnto scale.

Example Klystron

Vacuum devices or vacuum electron devices, such as klystrons, can beused to provided high power amplification of microwaves with outputpower up to tens of megawatts (MW). Typically, the klystron is a narrowbandwidth device with a bandwidth less than 10% of the input frequency,and in some examples, a bandwidth less than 1% of the input frequency.

Microwaves are a form of electromagnetic radiation with wavelengthsranging from one meter (1 m) to one millimeter (1 mm) with frequenciesbetween 300 megahertz (MHz; 1 m) and 300 gigahertz (GHz; 1 mm), whichcan include ultra high frequency (UHF; 300 MHz and 3 GHz), super highfrequency (SHF; 3 to 30 GHz), and extremely high frequency (EHF;millimeter wave; 30 to 300 GHz). With electromagnetic energy rangingfrom approximately 1 GHz to 100 GHz in frequency, the microwave spectrumcan be further categorized in bands, such as L (1-2 GHz), S (2-4 GHz), C(4-8 GHz), X (8-12 GHz), K_(u) (12-18 GHz), K (18-26.5 GHz), K_(a)(26.5-40 GHz), Q (33-50 GHz), U (40-60 GHz), V (50-75 GHz), W (75-110GHz), F (90-140 GHz), and D (110-170 GHz). Band L is associated withUHF, bands S through K_(a) are associated with SHF, and bands Q throughD are associated with EHF. Although, vacuum electron devices aretypically associated with microwaves, such as klystrons providingmicrowave amplification, the adjustments and approaches described hereinmay also apply to higher frequency devices, such as those operating inthe lower infrared spectrum, where the infrared electromagneticradiation includes wavelengths ranging from one millimeter (1 mm) to 700nanometers (nm) with frequencies between 300 GHz (1 mm) and 450terahertz (700 nm). Reference to the term “microwave” as used herein mayalso include frequencies in lower infrared spectrum. In one example theterm “microwave” includes frequencies between 300 MHz and 3 THz.

Although, the example vacuum devices are shown with adjustmentmechanisms to adjust an electron gun or cathode assembly componentswithin an evacuated enclosure, the mechanisms can also apply to othercomponents that are supported by a base within a vacuum chamber.

FIG. 1 is a block diagram of an example klystron 80. The N+2-cavityklystron 80 includes an electron gun 82 that is configured to emitelectrons, a resonator assembly 91 including N+2 cavities 92, 94, and96, and collector 90. The electron gun 82 includes a cathode 81 that isconfigured to generate a beam of electrons (or electron beam) 84 that isaccelerated towards an anode 83 by a voltage potential, V₀. The electronbeam 84 enters a tube with multiple cavities, referred to as resonantcavities (or “bunch” cavities) 92, 94, and 96 connected with drift tubes(or drift tube sections). The electron beam is coupled to the tubereferred to as electron beam coupling 97. The electron beam, at a firstresonant cavity, referred to as an input cavity or “buncher” cavity 92,is acted upon a radio frequency (RF) voltage 86. The klystron amplifiesthe RF input signal by converting the kinetic energy in the directcurrent (DC) electron beam 84 into radio frequency power.

The structure of the resonant cavities 92, 94, and 96 are designed tocreate standing waves at a specified resonant frequency, usually nearthe input frequency, which produces an oscillating voltage which acts onthe electron beam 84. The electric field causes the electrons to“bunch”, in that the electrons passing through the resonant cavity whenthe electric field opposes the motion of the electrons are slowed, andthe electrons passing through the resonant cavity when the electricfield is in the same direction as the motion of the electrons areaccelerated, causing the previously continuous electron beam to formbunches at or near the input frequency. To reinforce the bunching, aklystron may contain additional resonant cavities or “buncher” cavities94. In some examples, a “buncher” cavity (or “bunch” cavity) refers tothe first resonant cavity. In other examples, “buncher” cavities referto the first resonant cavity and the additional resonant cavities. Inthe example shown in FIG. 1, the klystron has N resonant cavities 94besides the input cavity 92 and the output cavity 96. Resonant cavities(e.g., N resonant cavities 94) are also referred to as intermediateresonant cavities. Typically, for conventional klystrons with normaltuning type configurations, each resonant cavity increases the gain byroughly 10 decibels (dB). Adding more resonant cavities can increase theRF gain or bandwidth. The electron beam 84 then passes through a “drift”tube in which the faster electrons catch up to the slower ones, creatingthe “bunches”, then through an output cavity or “catcher” cavity 96. Inthe output “catcher” cavity 96, each bunch of electrons enters thecavity at a time in the cycle when the electric field opposes theelectrons' motion, and thereby decelerates the electrons. Thus, thekinetic energy of the electrons is converted to energy of the electricfield, increasing the amplitude of the oscillations. The oscillationsexcited in the output cavity 96 are coupled out through a waveguide 87(or in other examples, a coaxial cable) to produce an amplified RFoutput signal 88. The coupling of the electric field to the waveguide 87is referred to as waveguide coupling 98. The spent electron beam, withreduced energy, is captured by a collector electrode or collector 90.

Example Sheet Beam Klystron

FIG. 2 is a diagram of an example sheet beam klystron (SBK) 100, whichis further described in U.S. Pat. No. 9,741,521, granted on Aug. 22,2017, entitled “Vacuum Electron Device Drift Tube,” which isincorporated by reference in its entirety. The SBK includes an electrongun assembly 110, a resonator assembly (or microwave cavity assembly)120, a microwave output waveguide assembly 130 including variouswaveguide components, and a collector assembly 140 that includes thecollector electrode (not shown). The resonator assembly 120 includes amagnetic return box 122 (which can also function as cooling box) thatcan enclose the resonant cavities (not labeled) and the drift tubesections (not labeled). The magnetic return box 122 can be enclosed onthe input side (or electron gun side) with an electron gun side polepiece (not shown) and enclosed on the output side (or collector side)with collector side pole piece 128. The electron gun side pole piece isnot shown in FIG. 2 so the resonant cavities and drift tube inside themagnetic return box 122 can be shown.

The electron gun assembly 110 includes the electron gun (not shown) thatincludes an electron emitter (not shown). The exterior of electron gunassembly 110 can include at least one vacuum ion pump 108, a vacuumpinch-off tube 114, and external base 118 (or electron gun base plate,electrode exterior base plate, or electrode external base plate). Thevacuum ion pump 108 is a type of vacuum pump capable of reachingpressures as low as 10E-11 millibars (mbar) under ideal conditions. Insome embodiments, the pressure the vacuum pump is capable of reaching isdifferent. The vacuum ion pump ionizes gas within the vacuum device andemploys a strong electrical potential, typically 3-7 kilovolts (kV),which allows the ions to accelerate into and be captured by a solidelectrode and its associated features. The vacuum pinch-off tube 114 isthe tube that is used to remove gas molecules from a sealed volume usingan external pump in order to leave behind a vacuum in the vacuum device.Once the vacuum is achieved, the tube is crimped or pinched-off andsealed to maintain the vacuum without a main vacuum pump. The vacuumpinch-off tube 114 can extend from the external base 118. The externalbase 118 can also support cathode heater connectors 112 (or cathodeheater electrical connectors) and adjustable support assemblies 116 (oradjustable cathode supports, adjustable support, translating shaft orcolumn, or cathode alignment mechanism or indexers). The cathode heaterconnectors 112 provide electrical connection between a cathode heaterand an electrical power supply that is external to the SBK 100.Typically, the components and structures of the electron gun assembly110, especially within the vacuum device, include materials compatiblefor ultra high vacuum (UHV) conditions, such as stainless steel,nickel-cobalt ferrous (iron) alloys (Ni—Co—Fe alloy; e.g., Kovar),molybdenum (Mo), and tungsten (W). These materials often require aspecific level of strength to support applicable loading forces andbending moments.

Example Adjustable Support Assembly

Beam formation and transport being inherently three dimensional (3D) canaffect design of a vacuum device, such as electron gun design andmagnetic focusing design. The mechanical concerns are at least in partand possibly largely due to both supporting and aligning a relativelylarge and/or heavy electron gun (specifically the heater, cathode, andfocus electrode) as well as thermal and induced stress issues due to arelatively large cathode heater.

FIGS. 3A-3B, 4, 5, and 6A-6B illustrate the cathode assembly 150 that ispart of the electron gun assembly 110 of FIG. 2. FIGS. 3A-3B illustrateperspective views of the cathode assembly 150 with the outside housingof electron gun assembly 110 removed, FIGS. 4 and 5 illustrateperspective half cross-sectional views of the cathode assembly 150 withthe section across one adjustable support assembly 116, and FIGS. 6A-6Billustrate quarter cross-sectional views of the cathode assembly 150with the section across one adjustable support assembly 116. Theexternal base 118 supports the three adjustable support assemblies116A-C so the adjustable supports can be accessed and adjusted external(outside the vacuum) to the vacuum device. The cathode heater connectors112 are shown (two of the three) with the cathode heater connector hole(one of the three) or opening 113 (electron gun base cathode heaterconnector hole or opening, electrode exterior base cathode heaterconnector hole or opening, or electron gun base plate cathode heaterelectrical connector hole or opening) in the external base 118. Cathodeassembly components 152 (e.g., cathode, focus electrode, or heater) arerigidly supported by cathode support 154 that is coupled to an internalbase 156 (cathode base plate or interior base). FIGS. 3A-3B and 4 showsthe external form factor (instead of the actual components) of thecathode assembly components 152. The cathode support 154 can includecathode support openings or windows 155 to allow electrical couplingfrom the external plate (e.g., cathode heater connectors) to the cathodeassembly components 152 and to control radiation and conduction heatflow from cathode assembly components 152 to internal base 156. Theexternal base 118 and internal base 156 can include holes or openings113 and 157 to allow the cathode heater connectors 112 (or otherconnectors) to extend through the bases to interior of the cathodeassembly 150. The cathode base plate hole or opening 157 is an openingin the internal base 156 for a cathode heater connector 112. Theadjustable support assemblies 116 extends through an external basesupport hole or opening 119 (or electron gun base support hole oropening, electrode exterior base support hole or opening, or electrodeexternal base support hole or opening). The adjustable supportassemblies 116 provide an adjustable coupling between internal base 156and the external base 118 which allows three-point adjustment of thecathode assembly components 152 relative to the rest of the vacuumdevice (e.g., anode, resonant cavities, and drift tube). In an example,at least one of the adjustable support assemblies 116 provides fine tovery fine adjustments for cathode-to-anode spacing, focuselectrode-to-anode spacing, or other types of spacing whilesimultaneously providing mechanical support, which can provideadjustment to the cathode (or focus electrode or other cathode assemblycomponent 152) post-fabrication without disrupting the vacuum in thevacuum device or tube.

FIGS. 7-8 illustrate views of an adjustable support assembly 116. FIG. 7illustrates a cross-sectional view of the adjustable support assembly116, and FIG. 8 illustrates perspective cross-sectional view of theadjustable support assembly 116 with the section along the longitudinalaxis 172 a of the adjustable support assembly 116. As illustrated inFIGS. 7-8, the adjustable support assembly 116 can include a flexiblecomponent 160. The flexible component 160 is a structure that is capableof maintaining a vacuum seal while being deformed, such as bytranslation of a center portion relative to an outer perimeter. Theflexible component 160 may be semi-flexible, elastic, resilient, or thelike. Examples of the flexible component 160 include a thin-walleddiaphragm 160′ in FIG. 9A and metal bellows 160″ in FIG. 9B. AlthoughFIGS. 4-8 are illustrated using a diaphragm as the flexible component160, any flexible component 160 may be used. The adjustable supportassembly 116 also includes a spacer 162 (or plate standoff, platesleeve, or cathode base plate spacer), a threaded shaft 170 (or linearthreaded shaft with flange), an external base support assembly 191, anda threaded hole component 180.

In some embodiments, at least one electron component, such as anelectron gun or a cathode assembly component 152, is supported andmechanically attached to a structure, such as a base or a plate. In anexample, the internal base 156 within an evacuated enclosure is coupledto at least one adjustable support 116 that has some portion that isaccessible outside the evacuated enclosure enclosing a vacuum. The atleast one adjustable support 116 is adjustably coupled to an externalbase 118 forming at least a portion of the evacuated enclosure. Theinternal base 156 is within the evacuated enclosure and configured tosupport at least one cathode assembly component 152. The at least onecathode assembly component 152 includes a cathode, a focus electrode, aheater assembly, or the like. The at least one adjustable support 116includes a flexible component 160, a spacer 162, a threaded shaft 170,an external base support assembly 191, and a threaded hole component180. The flexible component 160 includes a flexible component periphery160 a that is in contact with the external base 118 or another supportfeature attached to the external base at a corresponding opening 119 ofthe external base 118.

In some embodiments, the threaded hole component 180 includes a drivebushing 184 with a nut 182. The drive bushing 184 is slidably engagedwith the base cap 190 at the base cap opening 192. The drive bushing 184with the nut 182 may be a single structure where the drive bushing 184rotates when the nut 182 is rotated. A snap ring 186 may constrainmovement of the threaded hole component 180 along the longitudinal axis172 a. In some embodiments, the snap ring 186 prevents outward movementof the threaded hole component 180 while the nut 182 contacting the basecap 190 prevents inward movement. In other embodiments, the snap ring186 may be disposed in a different location to constrain movement of thethreaded hole component 180 along the longitudinal axis 172 a. Inaddition, while a single snap ring 186 has been used as an example, inother embodiments, more snap rings and/or other retaining structures maybe used.

In some embodiments, a sleeve bearing 187 surrounds a portion of thedrive bushing 184 of the threaded hole component 180. The sleeve bearing187 is slidably engaged with the drive bushing 184. The sleeve bearing187 is disposed in an opening 192 in the base cap 190. The sleevebearing 187 is slidably engaged with the base cap 190 at the opening192. One or more snap rings such as an inner snap ring 188 and an outersnap ring 189 may constrain movement of the sleeve bearing 187 along thelongitudinal axis 172 a relative to the base cap 190. The snap ring 186may constrain movement of the threaded hole component 180 relative tothe sleeve bearing 187. As a result, the movement of the threaded holecomponent 180 relative to the base cap 190 and hence the external base118 may be constrained.

While a relative location of various snap rings has been used asexamples, in other embodiments, the connection between the threaded holecomponent 180 and the external base 118 may be formed in differentmanners. Any attachment technique may be used that allows the threadedhole component 180 to rotate about the longitudinal axis 172 a and beconstrained in a direction along the longitudinal axis 172 a.

FIG. 8A illustrates an expanded view of threads between a linear shaftand a drive bushing of an example adjustable support assembly. Referringto FIGS. 8 and 8A, the threaded hole component 180 includes threads 185that interface with threads 173 of the threaded shaft 170. In someembodiments, a length of a threaded engagement of the threaded portionof the threaded shaft 170 with the threaded hole component 180 is atleast two times the diameter of the threaded portion of the threadedshaft 170. As a result, movement of the threaded shaft 170 in adirection perpendicular to the longitudinal axis 172 a may be reduced.

FIG. 9A illustrates cross-sectional view of an adjustable supportassembly 116 with a diaphragm flexible component 160′, and FIG. 9Billustrates cross-sectional view of an adjustable support assembly 116with a bellows flexible component 160″. The flexible component 160 caninclude a bellows 160″ or a diaphragm 160′ that allows a portion of theadjustable support 116 (and internal base 156) to move relative to theexternal base 118 of the evacuated enclosure while maintaining thevacuum within the evacuated enclosure. Although a diaphragm 160′ and abellows 160″ are used as examples of a flexible component 160, in otherembodiments, the flexible component 160 may have a different structure.In some embodiments, the flexible component 160 includes vacuumcompatible materials with a maximum total mass loss (TML) of less thanabout 1% and a collected volatile condensable materials (CVCM) fromoutgassing of less than about 0.1% of starting materials at 398 K (125°C.) for at least 24 hours. The flexible component 160 may be formed of avariety of materials. In some embodiments, the materials may includecupronickel or the like.

The spacer 162 is positioned between a surface of the internal base 156and a center area 160 b, such as center areas 160′b and 160″b, of aninner side (i.e., vacuum side 169) of the flexible component 160. Thespacer 162 provides a gap between the internal base 156 and externalbase 118. An internal base fastener 158 (or cathode base plate fastener;e.g., bolt or screw) can be used to couple the spacer 162 to theinternal base 156. The spacer threads 164 (cathode base plate spacerthreads) of the internal base fastener 158 can be used to tighten thespacer 162 to the internal base 156. An internal base washer 159 (orcathode base plate washer) can be positioned between the internal basefastener 158 and the internal base 156 to provide a better contactbetween to the internal base 156 and internal base fastener 158. Theinternal base 156 may be recessed or indexed for the internal basefastener 158 or the internal base washer 159. A midsection of the spacer162 can include a gas release feature 168 (e.g., spacer hole, platespacer hole, spacer slot, or spacer bore) to allow the release ofoutgasses from the spacer 162. Outgassing (sometimes called offgassing)is the release of a gas that was dissolved, trapped, frozen or absorbedin a material or component.

The threaded shaft 170 (or threaded linear shaft) is coupled to thespacer 162 on an outer side (e.g., exposed or non-vacuum side 171) ofthe center area 160 b, such as center areas 160′b and 160″b, of theflexible component 160. The center area 160 b of the flexible componentis disposed or sandwiched between the spacer 162 and the threaded shaft170 to provide a vacuum seal at the center area 160 b of the flexiblecomponent 160. The threaded shaft 170 provides the mechanical attachment(e.g., rigid or fixed coupling) to the internal base 156 that is outsidethe vacuum. The threaded shaft 170 can include three sections: a shaftextension 176 that couples to the spacer 162, shaft flange 174 that canbe used to reduce torque on the threaded shaft, and linear shaft 172 (orthreaded portion of the threaded shaft 170) that can be used to adjustthe spacing between the internal base 156 and external base 118.Although both the shaft extension 176 and linear shaft 172 both have athreaded portion, the threads on the linear shaft 172 are designed toadjust the internal base 156 relative to the external base 118 thus asused herein, the threaded portion refers to the threads on the linearshaft 172. Shaft plate spacer threads 166 (or external male threads) onthe shaft extension 176 correspond to the shaft flange spacer threads(or internal female threads or threaded hole) on the spacer 162 and areused to tighten the spacer 162 to the threaded shaft 170. The externalbase support assembly 191 provides the supporting structure on theexternal base 118 for the threaded shaft 170.

In some embodiments, the shaft flange 174 extends radially from thelinear shaft 172. The shaft flange 174 of the threaded shaft 170 iscoupled to at least one aligning pin 178. The at least one aligning pin178 extends outward from the shaft flange 174 in a direction along thelongitudinal axis 172 a into a corresponding at least one aligning pinhole 194 of the base cap 190. The at least one aligning pin 178 isslidably engaged with the corresponding at least on aligning pin hole194. The interface of the at least one aligning pin 178 and the at leastone aligning pin hole 194 reduce movement of the threaded shaft 170 in adirection perpendicular to the longitudinal axis 172 a and/or reducerotation of the threaded shaft 170 about the longitudinal axis 172 a. Insome embodiments, reducing the potential rotation of the threaded shaft170 reduces torque on the flexible component 160.

The external base support assembly 191 provides the mechanical featureson the external base 118 to support the threaded shaft 170 and seal theflexible component periphery 160 a. The external base support assembly191 is coupled to the external base 118 at or near the at least oneopening 119 of the external base 118. The external base support assembly191 includes a base cap 190 (or electron gun base plate cap or baseplate cap) and an external base support 196 (or electron gun base platering or base plate ring). A portion of the base cap periphery 190 a iscoupled to the external base support 196. The external base support 196is coupled to the external base 118 at the at least one opening 119 ofthe external base 118. A portion of the base cap periphery 190 a iscoupled to the external base support 196. As shown, the base cap 190 andexternal base support 196 are shown as separate components. In otherexamples, the base cap 190 and external base support 196 can be a singlecomponent, or at least two components that are brazed or otherwisejoined together as a single component. The base cap 190 and externalbase support 196 can include mating features that allow the base cap 190and external base support 196 to be joined or fitted together. Theexternal base support assembly 191 is shown as a cylindrical or ringshape. In other examples, the external base support 196 can have acuboid, triangular prism, hexagonal prism, octagonal prism, or otherprism shape. The flexible component periphery 160 a is disposed orsandwiched between the external base 118 and the external base support190 to provide a vacuum seal at the flexible component periphery 160 a.The joint between the external base 118 and the external base support196 may be coupled together by a braze, a weld, or other adhesivemechanism that can withstand high temperatures. The external basesupport assembly 191 includes an external base support opening 192 and alinear shaft 172 of the threaded shaft 170 extends through the externalbase support opening 192. The external base support 196 includes anopening 197 through which the shaft flange 174 may be accessed.

The threaded hole component 180 is threadedly engaged with the linearshaft 172 of the threaded shaft 170 and configured to adjustably movethe threaded shaft 170 relative to the base cap 190. The linear shaftthreads 173 forming the threaded portion of the linear shaft 172 arethreadedly engaged with the drive bushing threads 185 of the threadedhole component 180, as illustrated in FIG. 8A. In some embodiments, thepitch of the threads can be fine or extra fine for fine adjustment.Pitch is the distance from the crest of one thread to the next, whichcan be defined in terms of threads per inch (TPI). A fine pitch andextra fine pitch can be defined by the Unified Thread Standard (UTS) orInternational Organization for Standardization (ISO) metric screwthreads.

The threaded hole component 180 is configured to adjustably move thethreaded shaft 170 relative to the base cap 190. The external basesupport assembly 191 is fixed to the external base 118. In particular,the external base support assembly 191 is fixed to the external basesuch that the external base support assembly 191 is constrained in adirection along the longitudinal axis 172 a.

In some embodiments, a jam nut 183 is used to fix the threaded shaft 170to the threaded hole component 180. For example, after adjusting theposition of the inner base 156 by the relative rotation of the threadedhole component 180 and the threaded shaft 170, the jam nut 183 may betightened against threaded hole component 180. While a jam nut 183 is anexample of a structure that can fix the threaded shaft 170 to thethreaded hole component 180, in other embodiments, other structures maybe used. For example, a shim may be used in place of or in addition tothe jam nut 183.

FIG. 10 is a block diagram of an example of an adjustable supportassembly in a vacuum device. In some embodiments, the adjustable supportassembly 1116 is part of a vacuum device including an enclosure 1200configured to enclose a vacuum. As described above, a variety of vacuumdevices may include such an enclosure 1200, such as an electron gun, asheet beam klystron, a round beam klystron, a multi-beam klystron, arelativistic klystron, a traveling wave tube, a gyrotron, a freeelectron laser, an electron microscope, an inductive output tube, or alinear accelerator. An adjustable support assembly 1116 may be part ofsuch vacuum devices. In some embodiments, the adjustable supportassembly 1116 may include a structure such as the adjustable supportassembly 116 described above. The adjustable support assembly 1116 isconfigured to adjustably couple an internal base 156 within theenclosure to an external base 118 forming at least a part of theenclosure 1200. The adjustable support assembly 1116 extends through theopening 119.

The adjustable support assembly 1116 includes a shaft 1172. In someembodiments, the shaft is similar to the threaded shaft 170. The shaft1172 extends along the longitudinal axis 172 a and is coupled to theinternal base 156. In some embodiments, the shaft 1172 may includestructures such as the linear shaft 172, the spacer 162, or the likedescribed above. In some embodiments the shaft 1172 may be a unitarystructure. In some embodiments, the shaft 1172 may be integrated withthe internal base 156.

A threaded component 1180 is threadedly engaged with either the supportassembly 1191 or the shaft 1172. In some embodiments, the threadedcomponent 1180 is coupled to the external base 118 through supportassembly 1191 such that the threaded component 1180 is axiallyconstrained in a direction along the longitudinal axis 172 a relative tothe external base 118 independent of the threaded shaft 1172. Thethreaded hole component 1180 may be similar to the threaded holecomponent 180 described herein and the shaft 1172 may be similar to thethreaded shaft 170 and have corresponding engaged threads. The supportassembly 1191 is axially constrained along the longitudinal axis 172 arelative to the external base 118. Thus, when the threaded component1180 is threadedly engaged with the shaft 1172, the shaft 1172 is alsoaxially constrained in the direction along the longitudinal axis 172 a.The coupling of the shaft 1172 to the internal base 156 results in therelative position also being axially constrained. In particular, theposition of the internal base 156 is axially constrained by the engagedthreads even if the jam nut 183 is not engaged with the threaded holecomponent 1180.

However, in other embodiments, the location of the threads may bedifferent. For example, in some embodiments, the support assembly 1191and the threaded component 1180 have the interfacing threads. Thus, therelative position of the threaded component 1180 and the supportassembly 1191 may be changed through rotation of the threaded component1180. In this example, the threaded component 1180 is rotatably coupledto the shaft 1172 and also axially constrained along the longitudinalaxis 172 a relative to the shaft 1172. As a result, the motion along thelongitudinal axis 172 a of the shaft 1172 is still constrained by anengagement of threads as described above; however, the interfacingthreads are in a different location.

A flexible component 160 is coupled to the external base 118 and thethreaded shaft 1172 such that the remainder of the opening is sealed.The flexible component 160 is coupled to each of the external base 118and the threaded shaft 1172 in a manner that creates a hermetic seal.Accordingly, a vacuum seal may be maintained while providing an amountof adjustability.

With an adjustable support structure 1116, the jam nut 183 may bedisengaged and the threaded hole component 1180 and/or the threadedshaft 1172 may be rotated relative to each other to adjust the relativeposition. In particular, the relative position may be adjusted while thevacuum device is under vacuum. The position is defined by the engagementof the threads of the threaded hole component 1180 and the threadedshaft 1172. Disengaging locking structures such as the jam nut 183 toallow adjustment does not cause the axial position to becomeunconstrained by the degree of disengagement of the locking structure.For example, if the jam nut 183 is disengaged by a centimeter, the axialrange of motion of the threaded shaft 1172 and hence, the internal base156 is not on the order of a centimeter. Rather, the axial range ofmotion is constrained by the engagement of the threads of the threadedhole component 1180 and the threaded shaft 1172

In particular electron gun structures, due to geometry, size, accuracyrequirements, or the like, having the cathode or focuselectrode-to-anode spacing “fixed” into the design by various indexingfeatures (often called “hard alignment”) can be very cumbersome, and attimes, not possible. A common approach is to utilize a three-pointcolumn structure (each point usually 120° apart) with a flexiblediaphragm for hermeticity that can adjust the entire structure by movingthe columns individually per a variety of combinations to modify thetilt and height of the cathode or focus electrode. These three columnstypically support the weight of the entire structure to preventexcessive stresses present within the thin-walled diaphragms. Currentdesigns provide limited control and often have separate features forlinear adjustments and mechanical support. When releasing the mechanicalsupport for linear adjustments of the columns, the structure is at alevel of risk. In some embodiments, an extra-fine threaded drive bushinglinearly translates an accompanying shaft with the same threads. Arelatively large amount of threads are engaged so the surface areasupporting the weight of the structure is much greater than othermethods used. The fine thread pitch offers very controlled lineartranslation and since thread engagement is present at all times, themechanical support is consistent throughout all processing. Since therisk of temporarily loosing mechanical support during spacingadjustments is reduced, adjustments can confidently be executed at timesotherwise not recommended, for example when the device is under vacuumor operating.

FIG. 11A-B are block diagrams of examples of support assemblies with athermal dissipative structure according to some embodiments. Referringto FIG. 11A, in some embodiments, a thermal dissipative strap assembly1210 is part of a vacuum device including an enclosure 1200 configuredto enclose a vacuum. As described above, a variety of vacuum devices mayinclude such an enclosure 1200, such as an electron gun, a sheet beamklystron, a round beam klystron, a multi-beam klystron, a relativisticklystron, a traveling wave tube, a gyrotron, a free electron laser, anelectron microscope, an inductive output tube, or a linear accelerator.

The enclosure 1200 includes an external base 118 and an internal base156 similar to those described above. The internal base 156 is disposedwithin the enclosure and coupled to the external base 118 throughsupport assembly 216. In some embodiments, the support assembly 216 maybe adjustable such as the adjustable support assembly 116 or 1116described above; however, in other embodiments, the support assembly 216may be adjustable but have a configuration different from the variousadjustable support assemblies described herein. In addition, in someembodiments, the support assembly 216 may be fixed and not adjustable.

The thermal dissipative strap assembly 1210 is coupled to the externalbase 118 and the internal base 156. The thermal dissipative strapassembly 1210 includes an internal base thermal conductive base 1220, anexternal base thermal conductive base 1230, and a flexible thermaldissipative strap 1212 coupling the internal base thermal conductivebase 1220 to the external base thermal conductive base 1230. As will bedescribed in further detail below, more than one thermal dissipativestrap assembly 1210 may couple the external base 118 to the internalbase 156.

Heat flow 1240 and 1242 represent the flow of heat from the internalbase 156 to the external base 118. Heat flow 1240 represents the heatflow through a thermal dissipative strap assembly 1210. Heat flow 1242represents the heat flow through a support assembly 216. In someembodiments, a magnitude of the heat flow 1240 is greater than amagnitude of the heat flow 1242; however, in other embodiments, therelative magnitudes may be different. Regardless, at least some heatflows 1240 through the thermal dissipative strap assembly 1210 thatwould otherwise have flowed through the support assembly 216. Theredirection of the heat reduces the operating temperature of the supportassembly 216.

The flexible thermal dissipative strap 1212 may take different forms. Insome embodiments, the flexible thermal dissipative strap 1212 includes abent flat metal structure. In other embodiments, the flexible thermaldissipative strap 1212 includes a bent round, cylindrical, or ellipsoidshaped metal structure. In particular, the flexible thermal dissipativestrap 1212 may be formed to flexibly deform through a range of relativemotion of the internal base 156 and the external base 118. The shape ofthe flexible thermal dissipative strap 1212 may accommodate such motion,such as through bends or other flexible forms given the properties ofthe material of the flexible thermal dissipative strap 1212.

In some embodiments, the external base 118 includes a heat sink 240disposed on an opposite surface to a surface where the external basethermal conductive base 1230 contacts the external base 118. As aresult, heat that is conducted to the external base thermal conductivebase 1230 may be dissipated through the external base 118 and the heatsink 240.

In some embodiments, a thermal conductivity of the internal base thermalconductive base 1220 is greater than a thermal conductivity of theinternal base 156, or the thermal conductivity of the external basethermal conductive base 1230 is greater than a thermal conductivity ofthe external base 118. In some embodiments, the thermal conductivity ofthe thermal dissipative strap assembly 1210 is greater than the thermalconductivity of supporting structure 216.

The thermal dissipative strap assembly 1210 may be formed of a varietyof materials. For example, the thermal dissipative strap assembly 1210may be formed from materials with high thermal conductivity, vacuumcompatible materials, or the like. In some embodiments, the materialsmay include oxygen-free copper (OFC), oxygen-free electronic (OFE)copper, or oxygen-free high thermal conductivity (OFHC) copper, or thelike. In some embodiments, the materials may include gold or platinum.In some embodiments, the at least one thermal dissipative strap assemblyincludes vacuum compatible materials with a maximum total mass loss(TML) of less than about 1% and a collected volatile condensablematerials (CVCM) from outgassing of less than about 0.1% of startingmaterials at 398 K (125° C.) for at least 24 hours. Although particularparameters of vacuum compatible materials have been used as examples, inother embodiments, vacuum compatible materials may have differentparameters.

In some embodiments, the material of the thermal dissipative strapassembly 1210 may be selected based on the thermal conductivity ratherthan structural properties. That is, the thermal dissipative strapassembly 1210 may not provide significant structural support. However,as the support structure 216 provides the structural support for theinternal base 156 and any mounted components, the thermal dissipativestrap assembly 1210 need not be a material that is capable of providingthat structural support in the same or similar configuration.

As described above, a vacuum device may include at least one cathodeassembly component 152, such as a cathode, a focus electrode, heater,similar components, or the like that are supported by the internal base156. Heat from the at least one cathode assembly component 152 that isconducted to the internal base 156 may be dissipated through one or morethermal dissipative strap assemblies 1210.

Although the internal base thermal conductive base 1220 is illustratedas being disposed on the internal base 156 on a side opposite to thatfacing the external base 118, in other embodiments, the internal basethermal conductive base 1220 may be disposed in other locations. Forexample, the internal base thermal conductive base 1220 may be disposedon the side of the internal base 156 facing the external base. Inanother example, the internal base thermal conductive base 1220 may bedisposed on an edge of perimeter 156 a of the internal base 156.

Referring to FIG. 11B, in some embodiments, the thermal dissipativestrap assembly 1210 a is similar to the thermal dissipative strapassembly 1210; however, the thermal dissipative strap assembly 1210 aincludes an external thermal conductive base 1230 a that is attached toa wall 118 a of the enclosure 1200 a. For example, wall 118 a may be acylindrical wall of a vacuum enclosure 1200 a. An enclosure thermalconductive base 1230 a contacts the wall 118 a. As a result, heat thatis collected on the internal base 156 may be dissipated through thethermal dissipative strap assembly 1210 a to a location other than thoseassociated with the external base 118. In some embodiments, the wall 118a may be attached to the external base 118. However, in otherembodiments, other intervening structures may be present.

Although the enclosure thermal conductive base 1230 a has been describedas being attached to a portion of the enclosure other than the externalbase 118, in other embodiments, the enclosure thermal conductive base1230 a may be attached to the external base 118 and form an externalbase thermal conductive base 1230.

Example Thermal Dissipative Strap Assembly

FIGS. 12A-12B illustrate views of an example thermal dissipative strapassembly. In some embodiments, the thermal dissipative strap assembly210 may be used as the thermal dissipative strap assembly 1210. Thethermal dissipative strap assembly 210 includes a thermal dissipativestrap 212 coupled between an internal base thermal conductive base 220and an external base thermal conductive base 230. The internal basethermal conductive base 220 and the external base thermal conductivebase 230 are examples of the internal base thermal conductive base 1220and the external base thermal conductive base 1230 described above.

In some embodiments, the internal base thermal conductive base 220 andthe external base thermal conductive base 230 each have a cylindrical,disk, or puck shape. However, in other embodiments, the shape of theinternal base thermal conductive base 220 and the external base thermalconductive base 230 may be different. In addition, although the internalbase thermal conductive base 220 and the external base thermalconductive base 230 are illustrated as having the same size and shape,in some embodiments, the size and/or shape of the internal base thermalconductive base 220 and the external base thermal conductive base 230may be different from each other.

The internal base thermal conductive base 220 and the external basethermal conductive base 230 are illustrated as having generally the sameorientation. However, the internal base thermal conductive base 220 andthe external base thermal conductive base 230 may have differentorientations based on how the internal base thermal conductive base 220and the external base thermal conductive base 230 are attached to theinternal base 156 and external base 118, respectively.

The internal base thermal conductive base 220 is attached to the thermaldissipative strap 212 by thermal conductive base fastener 222.Similarly, the external base thermal conductive base 230 is coupled tothe thermal dissipative strap 212 by thermal conductive base fastener232. The thermal conductive base fasteners 222 and 232 may also attachthe internal base thermal conductive base 220 and the external basethermal conductive base 230 to the internal base 156 and the externalbase 118 or wall 118 a. Although fasteners 222 and 232 are used asexamples, in other embodiments, the thermal dissipative strap 212 may beattached to the internal base thermal conductive base 220 and theexternal base thermal conductive base 230 by brazing, welding, or otherthermally conductive attachment techniques.

The shape of the thermal dissipative strap 212 is an example of a shapethat can accommodate a range of motion between surfaces on which theinternal base thermal conductive base 220 and the external base thermalconductive base 230 are mounted. In this example, the path of thethermal dissipative strap 212 is not the shortest possible between theinternal base thermal conductive base 220 and the external base thermalconductive base 230. As a result, the thermal dissipative strap 212 maydeform as the relative position of the internal base thermal conductivebase 220 and the external base thermal conductive base 230 changeswithin a given range.

FIGS. 13-16 illustrate a variety of views an example cathode assemblywith thermal dissipative strap assemblies. In this particular example,FIG. 13 illustrates a perspective cross-sectional view of an examplecathode assembly with adjustable support assemblies 116, thermaldissipative strap assemblies 210, and cathode heater connectors 112. Thecathode assembly may be similar to those described above in FIGS. 2-9B.The cathode heater connectors 112 are examples of electrical connectionsto cathode assembly components 152 that may conduct heat; however, othercathode assembly components 152 may also conduct and generate heat.

One or more thermal dissipative strap assemblies 210 may be coupledbetween the external base 118 and the internal base 156. The thermaldissipative strap assemblies 210 may be similar to the thermaldissipative strap assembly 1210 described above. The thermal dissipativestrap assemblies 210 are disposed along an outer perimeter 156 a of theinternal base 156. In some embodiments, the internal base 156 has agenerally cylindrical or toroidal shape. At least some heat that isconducted from the cathode assembly components 152 may be dissipatedthrough the internal base 156 through the thermal dissipative strapassemblies 210 to the external base 118 rather than through theadjustable support structure 116.

FIG. 14A-14B illustrate perspective views of an example cathode assemblywith adjustable support assemblies 116 and thermal dissipative strapassemblies 210. FIG. 14C illustrates a perspective view of base plateindexing for thermal dissipative strap assemblies 210 and adjustablesupport assemblies. FIG. 15 illustrates a top view of an example cathodeassembly with adjustable support assemblies 116, thermal dissipativestrap assemblies 210, and cathode heater connectors 112.

Referring to FIGS. 14A-14B, the adjustable support assemblies 116A-Ccontact the internal base 156 at corresponding contact locations 117. Insome embodiments, the internal base thermal conductive bases 220 of thethermal dissipative strap assemblies 210A-F are disposed on the internalbase 156 among contact locations 117 of the adjustable supportassemblies 116A-F to the internal base. For example, each of the contactlocations 117 is adjacent to a corresponding one of the internal basethermal conductive bases 220. That thermal conductive base 220 may actas a local heat sink to dissipate heat from the local area adjacent thecontact location 117. In some embodiments, each contact location 117 isadjacent to a corresponding two of the internal base thermal conductivebases 220.

This example includes, three adjustable support assemblies 116A-C. Asdescribed above, the three adjustable support assemblies 116A-C may forma three-point column structure for the internal base 156. The threeadjustable support assemblies 116A-C are associated with six thermaldissipative strap assemblies 210A-F. As illustrated, for each of thecontact locations 117A-C, the corresponding adjacent thermal conductivebases 220 of the thermal dissipative strap assemblies 210 are generallyon opposite sides of that contact location 117. As a result, heatflowing from multiple directions towards the contact location 117 andhence, the corresponding adjustable support assembly 116 will bereduced. In addition, two of the thermal dissipative strap assembles 210are disposed between each pair of adjustable support assemblies 116. Forexample, thermal dissipative strap assemblies 210B and 210C are disposedbetween the adjustable support assemblies 116A and 116B.

While the number of thermal dissipative strap assemblies 210 that istwice the number of adjustable support assemblies 116 is illustrated asan example, in other embodiments the number may be different. In someembodiments include only one adjustable support assembly 116 andmultiple thermal dissipative strap assemblies 210 while otherembodiments include multiple adjustable support assemblies 116 and onlyone thermal dissipative strap assembly 210. Other embodiments havedifferent numbers of multiple adjustable support assemblies 116 andmultiple thermal dissipative strap assemblies 210.

FIG. 14C illustrates a perspective view of base plate indexing forthermal dissipative strap assemblies and adjustable support assemblies.In some embodiments, the internal base 156 includes at least one recess224 configured to receive the internal base thermal conductive base 220.In some embodiments, the external base 118 includes at least one recess234 configured to receive the external base thermal conductive base 230.As illustrated, six recesses 224A-F and six recesses 234A-F correspondto locations where internal base thermal conductive bases 220A-F andexternal base thermal conductive bases 230A-F are recessed and attachedto the corresponding internal base 156 or external base 118.

FIG. 16 illustrates a perspective view of an example cathode assemblywith three thermal dissipative strap assemblies. As described above, insome embodiments, for a given number of adjustable support structures116, the number of thermal dissipative strap assemblies 210 may vary. Asillustrated, three thermal dissipative strap assemblies 210A-C areincluded with the three adjustable support structures 116A-C. Each ofthe thermal dissipative strap assemblies 210A-C is disposed between apair of the adjustable support structures 116A-C. For example, thermaldissipative strap assembly 210A is between adjustable support structures116A and 116B.

In some embodiments, each of the thermal dissipative strap assemblies210A-C is closer to a corresponding one of the adjustable supportstructures 116A-C. However, in other embodiments, one or more of thethermal dissipative strap assemblies 210A-C may be equidistant from twoor more of the adjustable support structures 116A-C.

In some embodiments including large klystrons, such as those configuredto operate in L, S, C, and X bands, and in particular sheet beamklystrons, the cathode and heater assembly can be relatively large. Theweight of the cathode heater assembly and the thermal load from thecathode heater may constrain potential structural materials, structuralconfigurations, or the like. Where the support structures are also theonly path for thermal dissipation, the additional stresses (beyondgravity) from the thermal loading can be detrimental since stresses canlead to and exceed the yield strength of the material. The materialsdescribed above that may be used as structural materials may not exhibitthe highest thermal conductivity. In addition, the support structuresmay have minimal cross-sectional area that decreases thermal conductiveperformance.

When using a thermal dissipation strap assembly 210 or 1210 as describedherein, another path for thermal dissipation is created. In particular,another path for thermal dissipation that may not be optimized forstructural support is included. In some embodiments, the thermaldissipation strap assembly 210 or 1210 is flexible and does not providesignificant structural support between the external base 118 and theinternal base 156. As described above, the material of the thermaldissipation strap assembly 210 or 1210 may be selected to optimizethermal conductivity. However, the additional path or paths for thermaldissipation decrease thermal loading on the electron gun supportstructure, which decreases stresses (σ). The additional thermalconductive paths redirect heat and thermal stresses away from otherfeatures intended solely for mechanical support. The use of the thermaldissipative strap assemblies 210 or 1210 described herein may allowdesigns with thermal dissipation levels that would otherwise exceed thestructural capabilities of the materials of the support structure alone.Alternatively, in some embodiments, a smaller support structure can beused if a limiting factor on the size of the support structure is a needof the support structure to handle a given thermal dissipation within anacceptable failure rate.

Some vacuum devices include electron components (or microwavecomponents), such as an electron gun or a cathode assembly component,are aligned with other features of the vacuum device. Conventionally,for example, the electron components are aligned (i.e., a roughalignment) to the other features of the vacuum device and then thevacuum device is evacuated to put the device under vacuum. Usually, theelectron components are internal components that may not be accessibleor adjusted on the exterior of the vacuum device (i.e., outside thevacuum). Thus, a conventional vacuum device may not permit additional orfine adjustments of the electron components to provide a fine alignmentof the electron components to the other features of the vacuum device.With such a conventional vacuum device, if the initial/rough alignmentof the electron components performed prior to putting the device undervacuum along with other corrective mechanisms (e.g., focusing magnets)is not sufficient or adequate, the vacuum device may not operateproperly and may even fail. In some cases, the conventional vacuumdevice may be damaged by the slight misalignment. In other cases, thevacuum needs to be broken, the conventional vacuum device is at leastpartially disassembled, the electron components are realigned, thedevice is reassembled, and the device is put under vacuum again, whichprocess can be iterative, time consuming, and expensive.

Often at least one electron component, such as an electron gun or acathode assembly component 152, is supported and mechanically attachedto a structure, such as a base or a plate 156. In an example, theinternal base 156 within an evacuated enclosure is coupled to at leastone adjustable support 116 that has some portion that is accessibleoutside the evacuated enclosure enclosing a vacuum. The at least oneadjustable support is adjustably coupled to an external base 118 formingat least a portion of the evacuated enclosure. The internal base 156 iswithin the evacuated enclosure and configured to support at least onecathode assembly component 152. The at least one cathode assemblycomponent 152 includes a cathode, a focus electrode, a heater assembly,a combination of similar components, or the like. The at least oneadjustable support includes a flexible component 160, a spacer 162, athreaded shaft 170, an external base support assembly 191, and athreaded hole component 180. The flexible component includes a flexiblecomponent periphery that is in contact with the external base 118 atleast one opening 119 of the external base. The flexible component caninclude a bellows 160″ or a diaphragm 160′ that allows the adjustablesupport 116 (and internal base 156) to move relative to the externalbase 118 of the evacuated enclosure while maintaining the vacuum withinthe evacuated enclosure. The spacer 162 is positioned between a surfaceof the internal base 156 and a center area of an inner side (i.e.,vacuum side) of the flexible component. The spacer 162 provides a gapbetween the internal base 156 and external base 118. The threaded shaft170 (or threaded linear shaft) is coupled to the spacer 162 on thecenter area of an outer side (e.g., exposed or non-vacuum side) of theflexible component 160. The center area of the flexible component 160 isdisposed or sandwiched between the spacer 162 and the threaded shaft 170to provide a vacuum seal at the center area of the flexible component160. The threaded shaft 170 provides the mechanical attachment (e.g.,rigid or fixed coupling) outside the vacuum to the internal base 156.The external base support assembly 191 is coupled to the external baseat the at least one opening of the external base. The flexible component160 periphery is disposed or sandwiched between the external base 118and the external base support 196 to provide a vacuum seal at theflexible component periphery 160 a. The external base support assembly191 includes an external base support opening 192 and a threaded portion172 of the threaded shaft 170 extends through the external base supportopening 192. The external base support assembly 191 provides themechanical features on the external base to support the threaded shaft170 and seal the flexible component periphery 160 a. The threaded holecomponent 180 is threadedly engaged with the threaded portion 172 of thethreaded shaft 170 and configured to adjustably move the threaded shaftrelative to the external base support assembly 191.

In another example, the external base support assembly 191 includes anexternal base support 196 and a base cap 190. The external base support196 is coupled to the external base at the at least one opening of theexternal base. The flexible component periphery 160 a is disposed orsandwiched between the external base 196 and the external base support196 to provide a vacuum seal at the flexible component periphery 160 a.The base cap 190 includes a base cap opening and a base cap periphery190 a. The external base support opening includes the base cap opening192. A portion of the base cap periphery 190 a is coupled to theexternal base support 196, and the threaded portion 172 of the threadedshaft 170 extends through the base cap opening. The threaded holecomponent is configured to adjustably move the threaded shaft relativeto the base cap 190.

The electron components (or microwave components), such as an electrongun or a cathode assembly component 152, can generate an excessiveamount of heat and thermal stress (i.e., high thermal load) on thesupport features and structure, such as the adjustable support. The heatand thermal stresses on the support features and structure can lead tostress values greater than the yield strength of support features andstructure causing the support features and structure to warp, bend, orfail, which can cause misalignment of the electron components with therest of the device. In some examples with an adjustable support (e.g.,116), the heat and thermal stresses can weld or otherwise fuse theadjustable features (e.g., 172, 173, 180, and 185) together so theadjustable support is no longer adjustable.

In an example, at least one thermal dissipative strap assembly 210 canbe used to dissipate heat and relieve thermal stresses on the supportfeatures and structure, such as the adjustable support 116. For example,the vacuum device includes an evacuated enclosure with an external base118, an internal base 156 within the evacuated enclosure, and the atleast one thermal dissipative strap assembly 210. The at least onethermal dissipative strap assembly includes an internal base thermalconductive base 220 in contact with the internal base 156, an externalbase thermal conductive base 230 in contact with the external base, anda flexible thermal dissipative strap 212 coupling the internal basethermal conductive base to the external base thermal conductive base.

In another example, the internal base 156 includes at least one recess224 configured to receive the internal base thermal conductive base 220or the external base 118 includes at least one recess 234 configured toreceive the external base thermal conductive base 230. In aconfiguration, the flexible thermal dissipative strap includes a bentflat metal structure. For example, the bent flat metal structure canhave at least 3 corners along its length (long side). In anotherconfiguration, the flexible thermal dissipative strap includes a bentround, cylindrical, or ellipsoid shaped metal structure, which can bendand flex with movement between the internal base 156 and external base.

In another example, a thermal conductivity of the internal base thermalconductive base 220 is greater than a thermal conductivity of theinternal base 156, or the thermal conductivity of the external basethermal conductive base 230 is greater than a thermal conductivity ofthe external base 118. A thermal conductive base with a high thermalconductivity can help conduct heat away from the support features andstructure. In another example at least one thermal dissipative strap 212has a higher thermal conductivity than the adjustable support assembly116. In another example, the at least one thermal dissipative strapassembly includes vacuum compatible materials with a maximum total massloss (TML) of less than 1% and a collected volatile condensablematerials (CVCM) from outgassing of less than 0.1% of starting materialsat 398 K (125° C.) for at least 24 hours. In an example, the at leastone thermal dissipative strap assembly includes bake out materials thatcan withstand at least 375° C. with minimal outgassing and minimaldeformation. In another example, the at least one thermal dissipativestrap assembly includes bake out materials that can withstand at least450° C. with minimal outgassing and minimal deformation. In anotherexample, the at least one thermal dissipative strap assembly includesoxygen-free copper (OFC), oxygen-free electronic (OFE) copper, oroxygen-free high thermal conductivity (OFHC) copper. In another example,the at least one thermal dissipative strap assembly includes gold orplatinum.

In another example, the at least one thermal dissipative strap assembly210 includes a thermal conductive base fastener 222 coupling theinternal base thermal conductive base 220 to the internal base 156 or athermal conductive base fastener 232 coupling the external base thermalconductive base 230 to the external base 118. In another example, theexternal base includes a heat sink 240 on an opposite surface to asurface where the external base thermal conductive base makes contactwith the external base.

In another example, the at least one cathode assembly component 152includes a focus electrode or cathode. In another example, the vacuumdevice includes an electron gun or a sheet beam klystron.

Some embodiments include an enclosure 1200 configured to enclose avacuum, the enclosure 1200 including an external base 118 including anopening; an internal base 156 within the enclosure 1200; and anadjustable support assembly 116 or 1116 adjustably coupling the internalbase 156 to the external base 118 and extending through the opening, theadjustable support assembly 116 or 1116 comprising: a threaded shaft 170extending along a longitudinal axis 172 a and coupled to the internalbase 156; a threaded hole component 180 threadedly engaged with thethreaded shaft 170 and coupled to the external base 118 such that thethreaded hole component 180 is axially constrained in a direction alongthe longitudinal axis 172 a relative to the external base 118independent of the threaded shaft 170; and a flexible component 160coupled to the external base 118 and the threaded shaft 170 and sealingthe opening.

In some embodiments, the flexible component 160 comprises a periphery incontact with the external base 118 at the at least one opening; thevacuum device further comprises a spacer 162 positioned between asurface of the internal base 156 and an inner side of a center area ofthe flexible component 160; and the threaded shaft 170 is coupled to thespacer 162 on an outer side of the center area of the flexible component160, wherein the center area of the flexible component 160 is disposedbetween the spacer 162 and the threaded shaft 170.

In some embodiments, the flexible component 160 includes at least one ofa bellows 160″ and a diaphragm 160′.

In some embodiments, the adjustable support assembly 116 or 1116 furthercomprises: an external base support 196 coupled to the external base 118at the at least one opening of the external base 118; and a base cap 190including a base cap opening and a base cap 190 periphery; wherein: aportion of the base cap 190 periphery is coupled to the external basesupport 196; a threaded portion of the threaded shaft 170 extendsthrough the base cap opening; and the threaded hole component 180 isconfigured to adjustably move the threaded shaft 170 relative to thebase cap 190.

In some embodiments, the flexible component 160 comprises a peripherydisposed between the external base 118 and the external base support196.

In some embodiments, the threaded hole component 180 includes a drivebushing 184 including a drive nut 182; and an inner threaded portion ofthe drive bushing 184 is threadedly engaged with the threaded portion ofthe threaded shaft 170 and an outer perimeter of the drive bushing 184is slidably engaged with the base cap opening.

In some embodiments, the vacuum device further comprises a sleevebearing 187 slidably engaged with the base cap opening and slidablyengaged with the drive bushing 184.

In some embodiments, the vacuum device further comprises at least onedrive bushing snap ring 186 configured to restrain the sleeve bearing187 in a position relative to the drive bushing 184 in the directionalong the longitudinal axis 172 a of the threaded shaft 170.

In some embodiments, the vacuum device further comprises at least onesleeve bearing snap ring 188 configured to restrain the sleeve bearing187 in a position relative to the base cap 190 in the direction alongthe longitudinal axis 172 a of the threaded shaft 170.

In some embodiments, the vacuum device further comprises a jam nut 183or a shim configured to fix a position of the threaded shaft 170.

In some embodiments, the threaded shaft 170 includes a shaft flangeextending in a radial direction from the threaded shaft 170; the shaftflange includes at least one aligning pin 178; the base cap 190 includesat least one base cap 190 aligning pin hole 194; and the at least onealigning pin 178 is slidably engaged with the at least one base cap 190aligning pin hole 194.

In some embodiments, the external base support 196 includes an openingconfigured to allow access to a region of the threaded shaft 170 betweenthe base cap 190 and the flexible component 160.

In some embodiments, a length of a threaded engagement of a threadedportion of the threaded shaft 170 with the threaded hole component 180is at least two times a diameter of the threaded portion of the threadedshaft 170.

In some embodiments, the internal base 156 is configured to support atleast one cathode assembly component 152.

In some embodiments, the adjustable support assembly 116 or 1116 is oneof three adjustable supports configured to provide a three-point columnstructure for the at least one cathode assembly component.

In some embodiments, the at least one cathode assembly component 152includes a focus electrode or cathode.

In some embodiments, the vacuum device includes an electron gun, a sheetbeam klystron, a round beam klystron, a multi-beam klystron, arelativistic klystron, a traveling wave tube, a gyrotron, a freeelectron laser, an electron microscope, an inductive output tube, or alinear accelerator.

Some embodiments include an enclosure 1200 configured to enclose avacuum, the enclosure 1200 including an external base 118 including anopening; an adjustable support assembly 116 or 1116 coupled to theexternal base 118 and extending through the opening into the enclosure1200, the adjustable support assembly 116 or 1116 comprising: a threadedshaft 170 extending along a longitudinal axis 172 a; a threaded holecomponent 1180 threadedly engaged with the threaded shaft 170 andcoupled to the external base 118 such that the threaded hole component1180 is axially constrained in a direction along the longitudinal axis172 a relative to the external base 118 independent of the threadedshaft 170; and a flexible component 160 coupled to the external base 118and the threaded shaft 170 and sealing the opening.

In some embodiments, the adjustable support assembly 116 or 1116 furthercomprises an external base support assembly 191 coupled to the externalbase 118 and axially constrained along the longitudinal axis 172 arelative to the external base 118; and the threaded hole component 180is slidably engaged with the external base support assembly 191.

Some embodiments include an enclosure 1200 configured to enclose avacuum, the enclosure 1200 including an external base 118 including anopening; an internal base 156 within the enclosure 1200; an adjustablesupport assembly 116 or 1116 coupling the internal base 156 to theexternal base 118 and extending through the opening, the adjustablesupport assembly 116 or 1116 comprising: a shaft 1172 extending along alongitudinal axis 172 a; an external base support assembly 1191 coupledto the external base 118 and axially constrained along the longitudinalaxis 172 a relative to the external base 118; a threaded component 1180threadedly engaged with the external base support assembly 1191 andcoupled to the shaft 1172 such that the threaded component 180 isaxially constrained in a direction along the longitudinal axis 172 arelative to the shaft 1172 independent of the external base supportassembly 1191; and a flexible component 160 coupled to the external base118 and the shaft 1172 and sealing the opening.

Some embodiments include a vacuum device comprising means for enclosinga vacuum; means for supporting disposed within the means for enclosing avacuum; means for adjusting a position of the means for supporting; andmeans for axially constraining the means for adjusting the position ofthe means for supporting along a longitudinal axis 172 a of the meansfor adjusting the position of the means for supporting.

Examples of the means for enclosing a vacuum include the enclosure 1200or the vacuum device 100.

Examples of the means for supporting disposed within the means forenclosing a vacuum include an internal base 156.

Examples of the means for adjusting a position of the means forsupporting include the adjustable support structures 116 or 1116.

Examples of the means for axially constraining the means for adjustingthe position of the means for supporting along a longitudinal axis ofthe means for adjusting the position of the means for supporting includethe threaded hole component 180, the snap rings 186 and 187, the basecap 190, the external base support 196, and/or the sleeve bushing 187.

In some embodiments, the vacuum device further comprises means forrotationally constraining the means for adjusting the position of themeans for supporting about the longitudinal axis. Examples of the meansfor rotationally constraining the means for adjusting the position ofthe means for supporting about the longitudinal axis include thealigning pin 178, the aligning pin hole 194, and the external basesupport assembly 191 and 1191.

Some embodiments include an enclosure 1200 configured to enclose avacuum, comprising an external base 118 forming at least a portion ofthe enclosure 1200; an internal base 156 within the enclosure 1200; andat least one thermal dissipative strap assembly 210 or 1210, comprising:an internal base thermal conductive base 220 or 1220 in contact with theinternal base 156; an external base thermal conductive base 230 or 1230in contact with the external base 118; and a flexible thermaldissipative strap 212 or 1212 coupling the internal base thermalconductive base 220 or 1220 to the external base thermal conductive base230 or 1230.

In some embodiments, the internal base 156 includes at least one recessconfigured to receive the internal base thermal conductive base 220 or1220 or the external base 118 includes at least one recess configured toreceive the external base 118 thermal conductive base.

In some embodiments, the flexible thermal dissipative strap 212 or 1212includes a bent flat metal structure.

In some embodiments, the flexible thermal dissipative strap 212 or 1212includes a bent round, cylindrical, or ellipsoid shaped metal structure.

In some embodiments, the flexible thermal dissipative strap 212 or 1212includes a bent flat, round, cylindrical, or ellipsoid shaped metalstructure.

In some embodiments, a thermal conductivity of the internal base thermalconductive base 220 or 1220 is greater than a thermal conductivity ofthe internal base 156, or the thermal conductivity of the external basethermal conductive base 230 or 1230 is greater than a thermalconductivity of the external base 118 or the thermal conductivity of thethermal dissipative strap 212 or 1212 is greater than the thermalconductivity of the support assembly 116 or 1116 or 216.

In some embodiments, the at least one thermal dissipative strap assembly210 or 1210 includes vacuum compatible materials with a maximum totalmass loss (TML) of less than 1% and a collected volatile condensablematerials (CVCM) from outgassing of less than 0.1% of starting materialsat 398 K (125° C.) for at least 24 hours.

In some embodiments, the at least one thermal dissipative strap assembly210 or 1210 includes oxygen-free copper (OFC), oxygen-free electronic(OFE) copper, or oxygen-free high thermal conductivity (OFHC) copper.

In some embodiments, the vacuum device further comprises: a thermalconductive base fastener 222 or 232 coupling the internal base thermalconductive base 220 or 1220 to the internal base 156 or coupling theexternal base thermal conductive base 230 or 1230 to the external base118.

In some embodiments, the vacuum device further comprises: at least onecathode assembly component 152 supported by the internal base 156.

In some embodiments, the at least one cathode assembly component 152includes a focus electrode or cathode.

In some embodiments, the external base 118 includes a heat sink 240 onan opposite surface to a surface where the external base thermalconductive base 230 or 1230 makes contact with the external base 118.

In some embodiments, the vacuum device includes an electron gun, a sheetbeam klystron, a round beam klystron, a multi-beam klystron, arelativistic klystron, a traveling wave tube, a gyrotron, a freeelectron laser, an electron microscope, an inductive output tube, or alinear accelerator.

In some embodiments, the vacuum device further comprises an adjustablesupport assembly 116 or 1116 adjustably coupling the internal base 156to the external base 118 and extending through an opening in theexternal base 118, the adjustable support assembly 116 or 1116comprising: a threaded shaft 170 extending along a longitudinal axis 172a and coupled to the internal base 156; a threaded hole component 180threadedly engaged with the threaded shaft 170 and coupled to theexternal base 118 such that the threaded hole component 180 is axiallyconstrained in a direction along the longitudinal axis 172 a relative tothe external base 118 independent of the threaded shaft 170; and aflexible component 160 coupled to the external base 118 and the threadedshaft 170 and sealing the opening.

Some embodiments include an enclosure 1200 configured to enclose avacuum; an internal base 156 within the enclosure 1200; a plurality ofsupport assemblies 116, 216, or 1116 penetrating the enclosure 1200 andcontacting the internal base 156; and a plurality of thermal dissipativestrap assemblies 210 or 1210, each thermal dissipative strap assembly210 or 1210 comprising: an internal base thermal conductive base 220 or1220 in contact with the internal base 156; an enclosure thermalconductive base 1230 or 1230 a in contact with the enclosure 1200; and aflexible thermal dissipative strap 212 or 1212 coupling the internalbase thermal conductive base 220 or 1220 to the enclosure 1200 thermalconductive base; wherein the internal base thermal conductive bases 220or 1220 of the thermal dissipative strap assemblies 210 or 1210 aredisposed on the internal base 156 among contact locations of the supportassemblies 116, 216, or 1116 to the internal base 156.

In some embodiments, each of the contact locations of the supportassemblies 116, 216, or 1116 to the internal base 156 is adjacent to acorresponding one of the internal base thermal conductive bases 220 or1220.

In some embodiments, each of the contact locations of the supportassemblies 116, 216, or 1116 to the internal base 156 is adjacent to acorresponding two of the internal base thermal conductive bases 220 or1220.

In some embodiments, the support assemblies 116, 216, or 1216 comprisethree support assemblies 116, 216, or 1116 configured to provide athree-point column structure for the internal base 156; and the thermaldissipative strap assemblies comprise three thermal dissipative strapassemblies.

In some embodiments, the support assemblies 116, 216, or 1116 comprisethree support assemblies 116, 216, or 1116 configured to provide athree-point column structure for the internal base 156; the thermaldissipative strap assemblies comprise six thermal dissipative strapassemblies; and two of the thermal dissipative strap assemblies aredisposed between each pair of the three support assemblies 116, 216, or1116.

In some embodiments, the enclosure 1200 comprises an external base 118forming at least a portion of the enclosure 1200; and the enclosurethermal conductive base 1230 a is an external base thermal conductivebase 1230 disposed on the external base 118.

Some embodiments include a vacuum device comprising means for enclosinga vacuum; means for generating heat disposed within the means forenclosing the vacuum; means for supporting the means for generatingheat; and means for reducing the heat conducted to the means forenclosing the vacuum through the means for supporting the means forgenerating heat.

Examples of the means for enclosing a vacuum include enclosure 1200 andvacuum device 100.

Examples of the means for generating heat disposed within the means forenclosing the vacuum include the internal base 156 and the cathodeassembly components 152.

Examples of the means for supporting the means for generating heatinclude the support assemblies 216 or adjustable support assemblies 116or 1116.

Examples of the means for reducing the heat conducted to the means forenclosing the vacuum through the means for supporting the means forgenerating heat include thermal dissipative strap assemblies 210 or1210.

In some embodiments, the vacuum device further comprises means fordissipating heat disposed on a surface of the means for enclosing thevacuum opposite to a surface of the means for enclosing the vacuumcontacting the means for reducing the heat conducted to the means forenclosing the vacuum. Examples of the means for dissipating heat includethe heat sink 240.

All references recited herein are incorporated herein by specificreference in their entirety.

Although the features, characteristics, structures, devices, methods,and systems have been described in accordance with particularembodiments, one of ordinary skill in the art will readily recognizethat many variations to the particular embodiments are possible, and anyvariations should therefore be considered to be within the principles,concepts, and scope disclosed herein. Accordingly, many modificationsmay be made by one of ordinary skill in the art without departing fromthe principles, concepts, and scope of the appended claims. Furthermore,the described features, structures, or characteristics may be combinedin a suitable manner in one or more embodiments. In the previousdescription, numerous specific details are provided (e.g., examples oflayouts and designs) to provide a thorough understanding of embodimentsof the invention. One skilled in the relevant art will recognize,however, that the invention can be practiced without one or more of thespecific details, or with other methods, components, layouts, etc. Inother instances, well-known structures, components, or operations arenot shown or described in detail to avoid obscuring aspects of theinvention.

The claims following this written disclosure are hereby expresslyincorporated into the present written disclosure, with each claimstanding on its own as a separate embodiment. This disclosure includesall permutations of the independent claims with their dependent claims.Moreover, additional embodiments capable of derivation from theindependent and dependent claims that follow are also expresslyincorporated into the present written description. These additionalembodiments are determined by replacing the dependency of a givendependent claim with the phrase “any of the claims beginning with claim[x] and ending with the claim that immediately precedes this one,” wherethe bracketed term “[x]” is replaced with the number of the mostrecently recited independent claim. For example, for the first claim setthat begins with independent claim 1, claim 3 can depend from either ofclaims 1 and 2, with these separate dependencies yielding two distinctembodiments; claim 4 can depend from any one of claim 1, 2, or 3, withthese separate dependencies yielding three distinct embodiments; claim 5can depend from any one of claim 1, 2, 3, or 4, with these separatedependencies yielding four distinct embodiments; and so on.

Recitation in the claims of the term “first” with respect to a featureor element does not necessarily imply the existence of a second oradditional such feature or element. Reference throughout thisspecification to an “example” or an “embodiment” means that a particularfeature, structure, or characteristic described in connection with theexample is included in at least one embodiment of the invention. Thus,appearances of the words an “example” or an “embodiment” in variousplaces throughout this specification are not necessarily all referringto the same embodiment. Elements specifically recited inmeans-plus-function format, if any, are intended to be construed tocover the corresponding structure, material, or acts described hereinand equivalents thereof in accordance with 35 U.S.C. § 112 ¶ 6.Embodiments of the invention in which an exclusive property or privilegeis claimed are defined as follows.

What is claimed is:
 1. A vacuum device, comprising: an enclosureconfigured to enclose a vacuum, the enclosure including an external baseincluding an opening; an internal base within the enclosure; and anadjustable support assembly adjustably coupling the internal base to theexternal base and extending through the opening, the adjustable supportassembly comprising: a threaded shaft extending along a longitudinalaxis and coupled to the internal base; a threaded hole componentthreadedly engaged with the threaded shaft and coupled to the externalbase such that the threaded hole component is axially constrained in adirection along the longitudinal axis relative to the external baseindependent of the threaded shaft; and a flexible component coupled tothe external base and the threaded shaft and sealing the opening.
 2. Thevacuum device of claim 1, wherein: the flexible component comprises aperiphery in contact with the external base at the at least one opening;the vacuum device further comprises a spacer positioned between asurface of the internal base and an inner side of a center area of theflexible component; and the threaded shaft is coupled to the spacer onan outer side of the center area of the flexible component, wherein thecenter area of the flexible component is disposed between the spacer andthe threaded shaft.
 3. The vacuum device of claim 1, wherein theflexible component includes at least one of a bellows and a diaphragm.4. The vacuum device of claim 1, wherein the adjustable support assemblyfurther comprises: an external base support coupled to the external baseat the at least one opening of the external base; and a base capincluding a base cap opening and a base cap periphery; wherein: aportion of the base cap periphery is coupled to the external basesupport; a threaded portion of the threaded shaft extends through thebase cap opening; and the threaded hole component is configured toadjustably move the threaded shaft relative to the base cap.
 5. Thevacuum device of claim 4, wherein the threaded hole component includes adrive bushing including a drive nut; and an inner threaded portion ofthe drive bushing is threadedly engaged with the threaded portion of thethreaded shaft and an outer perimeter of the drive bushing is slidablyengaged with the base cap opening.
 6. The vacuum device of claim 4,further comprising a sleeve bearing slidably engaged with the base capopening and slidably engaged with the drive bushing.
 7. The vacuumdevice of claim 6, further comprising at least one drive bushing snapring configured to restrain the sleeve bearing in a position relative tothe drive bushing in the direction along the longitudinal axis of thethreaded shaft.
 8. The vacuum device of claim 6, further comprising atleast one sleeve bearing snap ring configured to restrain the sleevebearing in a position relative to the base cap in the direction alongthe longitudinal axis of the threaded shaft.
 9. The vacuum device ofclaim 4, wherein the threaded shaft is coupled to the base cap such thatthe threaded shaft is rotationally constrained about the longitudinalaxis.
 10. The vacuum device of claim 4, further comprising a jam nut ora shim configured to fix a position of the threaded shaft.
 11. Thevacuum device of claim 4, wherein: the threaded shaft includes a shaftflange extending in a radial direction from the threaded shaft; theshaft flange includes at least one aligning pin; the base cap includesat least one base cap aligning pin hole; and the at least one aligningpin is slidably engaged with the at least one base cap aligning pinhole.
 12. The vacuum device of claim 4, wherein the external basesupport includes an opening configured to allow access to a region ofthe threaded shaft between the base cap and the flexible component. 13.The vacuum device of claim 1, wherein a length of a threaded engagementof a threaded portion of the threaded shaft with the threaded holecomponent is at least two times a diameter of the threaded portion ofthe threaded shaft.
 14. The vacuum device of claim 1, wherein theinternal base is configured to support at least one cathode assemblycomponent.
 15. The vacuum device of claim 14, wherein the adjustablesupport assembly is one of three adjustable supports configured toprovide a three-point column structure for the at least one cathodeassembly component.
 16. The vacuum device of claim 14, wherein the atleast one cathode assembly component includes a focus electrode orcathode.
 17. The vacuum device of claim 1, wherein the vacuum deviceincludes an electron gun, a sheet beam klystron, a round beam klystron,a multi-beam klystron, a relativistic klystron, a traveling wave tube, agyrotron, a free electron laser, an electron microscope, an inductiveoutput tube, or a linear accelerator.
 18. A vacuum device, comprising:an enclosure configured to enclose a vacuum, the enclosure including anexternal base including an opening; an internal base within theenclosure; an adjustable support assembly coupling the internal base tothe external base and extending through the opening, the adjustablesupport assembly comprising: a shaft extending along a longitudinalaxis; an external base support assembly coupled to the external base andaxially constrained along the longitudinal axis relative to the externalbase; a threaded component threadedly engaged with the external basesupport assembly and coupled to the shaft such that the threadedcomponent is axially constrained in a direction along the longitudinalaxis relative to the shaft independent of the external base supportassembly; and a flexible component coupled to the external base and theshaft and sealing the opening.
 19. A vacuum device, comprising: meansfor enclosing a vacuum; means for supporting disposed within the meansfor enclosing a vacuum; means for adjusting a position of the means forsupporting; and means for axially constraining the means for adjustingthe position of the means for supporting along a longitudinal axis ofthe means for adjusting the position of the means for supporting. 20.The vacuum device of claim 19, comprising: means for rotationallyconstraining the means for adjusting the position of the means forsupporting about the longitudinal axis.